题解 | #禁止重复注册#

import sys

current_users = ['Niuniu','Niumei','GURR','LOLO']
new_users = ['GurR','Niu Ke Le','LoLo','Tuo Rui Chi']

current_users1 = [i.lower() for i in current_users]


for j in new_users:
        a = j.lower() in current_users1
        if a:
            print('The user name %s has already been registered! Please change it and try again!'%j)
        else:
            print('Congratulations, the user name %s is available!'%j)